### Eclipse Workspace Patch 1.0
#P org.eclipse.mylyn.tasks.ui
Index: src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskEditorAttachmentPart.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.mylyn/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskEditorAttachmentPart.java,v
retrieving revision 1.41
diff -u -r1.41 TaskEditorAttachmentPart.java
--- src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskEditorAttachmentPart.java	24 Jul 2009 12:05:45 -0000	1.41
+++ src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskEditorAttachmentPart.java	5 Sep 2009 19:56:02 -0000
@@ -34,11 +34,11 @@
 import org.eclipse.jface.window.ToolTip;
 import org.eclipse.mylyn.internal.provisional.commons.ui.CommonImages;
 import org.eclipse.mylyn.internal.tasks.core.TaskAttachment;
+import org.eclipse.mylyn.internal.tasks.ui.commands.OpenTaskAttachmentHandler;
 import org.eclipse.mylyn.internal.tasks.ui.util.TasksUiMenus;
 import org.eclipse.mylyn.internal.tasks.ui.wizards.TaskAttachmentWizard.Mode;
 import org.eclipse.mylyn.tasks.core.ITaskAttachment;
 import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
-import org.eclipse.mylyn.tasks.ui.TasksUiUtil;
 import org.eclipse.mylyn.tasks.ui.editors.AbstractTaskEditorPart;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.SelectionAdapter;
@@ -51,6 +51,7 @@
 import org.eclipse.swt.widgets.Menu;
 import org.eclipse.swt.widgets.Table;
 import org.eclipse.swt.widgets.TableColumn;
+import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.forms.events.ExpansionAdapter;
 import org.eclipse.ui.forms.events.ExpansionEvent;
 import org.eclipse.ui.forms.widgets.FormToolkit;
@@ -136,11 +137,7 @@
 				getTaskEditorPage().getAttributeEditorToolkit()));
 		attachmentsViewer.addOpenListener(new IOpenListener() {
 			public void open(OpenEvent event) {
-				if (!event.getSelection().isEmpty()) {
-					StructuredSelection selection = (StructuredSelection) event.getSelection();
-					ITaskAttachment attachment = (ITaskAttachment) selection.getFirstElement();
-					TasksUiUtil.openUrl(attachment.getUrl());
-				}
+				openAttachments(event);
 			}
 		});
 		attachmentsViewer.addSelectionChangedListener(getTaskEditorPage());
@@ -260,4 +257,24 @@
 		toolBarManager.add(attachFileAction);
 	}
 
+	protected void openAttachments(OpenEvent event) {
+		List<ITaskAttachment> attachments = new ArrayList<ITaskAttachment>();
+
+		StructuredSelection selection = (StructuredSelection) event.getSelection();
+
+		List<?> items = selection.toList();
+		for (Object item : items) {
+			if (item instanceof ITaskAttachment) {
+				attachments.add((ITaskAttachment) item);
+			}
+		}
+
+		if (attachments.isEmpty()) {
+			return;
+		}
+
+		IWorkbenchPage page = getTaskEditorPage().getSite().getWorkbenchWindow().getActivePage();
+
+		OpenTaskAttachmentHandler.openAttachments(page, attachments);
+	}
 }
Index: src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskAttachmentStorage.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.mylyn/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskAttachmentStorage.java,v
retrieving revision 1.4
diff -u -r1.4 TaskAttachmentStorage.java
--- src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskAttachmentStorage.java	5 Dec 2008 23:25:50 -0000	1.4
+++ src/org/eclipse/mylyn/internal/tasks/ui/editors/TaskAttachmentStorage.java	5 Sep 2009 19:56:02 -0000
@@ -23,6 +23,7 @@
 import org.eclipse.core.runtime.PlatformObject;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
 import org.eclipse.mylyn.tasks.core.AbstractRepositoryConnector;
 import org.eclipse.mylyn.tasks.core.ITask;
 import org.eclipse.mylyn.tasks.core.ITaskAttachment;
@@ -36,17 +37,6 @@
  * @author Steffen Pingel
  */
 public class TaskAttachmentStorage extends PlatformObject implements IStorage {
-
-	private static final String ATTACHMENT_DEFAULT_NAME = "attachment"; //$NON-NLS-1$
-
-	private static final String CTYPE_ZIP = "zip"; //$NON-NLS-1$
-
-	private static final String CTYPE_OCTET_STREAM = "octet-stream"; //$NON-NLS-1$
-
-	private static final String CTYPE_TEXT = "text"; //$NON-NLS-1$
-
-	private static final String CTYPE_HTML = "html"; //$NON-NLS-1$
-
 	private final TaskRepository taskRepository;
 
 	private final ITask task;
@@ -75,23 +65,8 @@
 	}
 
 	private static String getName(ITaskAttachment attachment) {
-		String name = attachment.getFileName();
-		// if no filename is set, make one up with the proper extension so
-		// we can support opening in that filetype's default editor
-		if (name == null || "".equals(name)) { //$NON-NLS-1$
-			String ctype = attachment.getContentType();
-			if (ctype.endsWith(CTYPE_HTML)) {
-				name = ATTACHMENT_DEFAULT_NAME + ".html"; //$NON-NLS-1$
-			} else if (ctype.startsWith(CTYPE_TEXT)) {
-				name = ATTACHMENT_DEFAULT_NAME + ".txt"; //$NON-NLS-1$
-			} else if (ctype.endsWith(CTYPE_OCTET_STREAM)) {
-				name = ATTACHMENT_DEFAULT_NAME;
-			} else if (ctype.endsWith(CTYPE_ZIP)) {
-				name = ATTACHMENT_DEFAULT_NAME + "." + CTYPE_ZIP; //$NON-NLS-1$
-			} else {
-				name = ATTACHMENT_DEFAULT_NAME + "." + ctype.substring(ctype.indexOf("/") + 1); //$NON-NLS-1$ //$NON-NLS-2$
-			}
-		}
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+
 		// treat .patch files as text files
 		if (name.endsWith(".patch")) { //$NON-NLS-1$
 			name += ".txt"; //$NON-NLS-1$
Index: src/org/eclipse/mylyn/internal/tasks/ui/actions/SaveAttachmentsAction.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.mylyn/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/actions/SaveAttachmentsAction.java,v
retrieving revision 1.1
diff -u -r1.1 SaveAttachmentsAction.java
--- src/org/eclipse/mylyn/internal/tasks/ui/actions/SaveAttachmentsAction.java	28 May 2009 09:13:39 -0000	1.1
+++ src/org/eclipse/mylyn/internal/tasks/ui/actions/SaveAttachmentsAction.java	5 Sep 2009 19:56:02 -0000
@@ -35,16 +35,6 @@
  */
 public class SaveAttachmentsAction extends Action {
 
-	private static final String ATTACHMENT_DEFAULT_NAME = "attachment"; //$NON-NLS-1$
-
-	private static final String CTYPE_ZIP = "zip"; //$NON-NLS-1$
-
-	private static final String CTYPE_OCTET_STREAM = "octet-stream"; //$NON-NLS-1$
-
-	private static final String CTYPE_TEXT = "text"; //$NON-NLS-1$
-
-	private static final String CTYPE_HTML = "html"; //$NON-NLS-1$
-
 	public SaveAttachmentsAction(String text) {
 		super(text);
 	}
@@ -66,7 +56,7 @@
 	 */
 	private void saveSingleAttachment(ITaskAttachment attachment) {
 		FileDialog fileChooser = new FileDialog(WorkbenchUtil.getShell(), SWT.SAVE);
-		fileChooser.setFileName(getAttachmentFilename(attachment));
+		fileChooser.setFileName(AttachmentUtil.getAttachmentFilename(attachment));
 
 		File initDirectory = getInitialDirectory();
 		if (initDirectory != null) {
@@ -123,7 +113,7 @@
 		}
 
 		for (ITaskAttachment attachment : attachments) {
-			String filename = getAttachmentFilename(attachment);
+			String filename = AttachmentUtil.getAttachmentFilename(attachment);
 			File file = getTargetFile(WorkbenchUtil.getShell(), directory, filename);
 			if (file != null) {
 				DownloadAttachmentJob job = new DownloadAttachmentJob(attachment, file);
@@ -160,26 +150,6 @@
 		}
 	}
 
-	private String getAttachmentFilename(ITaskAttachment attachment) {
-		String fname = attachment.getFileName();
-		// default name if none is found
-		if (fname.equals("")) { //$NON-NLS-1$
-			String ctype = attachment.getContentType();
-			if (ctype.endsWith(CTYPE_HTML)) {
-				fname = ATTACHMENT_DEFAULT_NAME + ".html"; //$NON-NLS-1$
-			} else if (ctype.startsWith(CTYPE_TEXT)) {
-				fname = ATTACHMENT_DEFAULT_NAME + ".txt"; //$NON-NLS-1$
-			} else if (ctype.endsWith(CTYPE_OCTET_STREAM)) {
-				fname = ATTACHMENT_DEFAULT_NAME;
-			} else if (ctype.endsWith(CTYPE_ZIP)) {
-				fname = ATTACHMENT_DEFAULT_NAME + "." + CTYPE_ZIP; //$NON-NLS-1$
-			} else {
-				fname = ATTACHMENT_DEFAULT_NAME + "." + ctype.substring(ctype.indexOf("/") + 1); //$NON-NLS-1$ //$NON-NLS-2$
-			}
-		}
-		return fname;
-	}
-
 	private File getInitialDirectory() {
 		String dirName = TasksUiPlugin.getDefault().getPreferenceStore().getString(
 				ITasksUiPreferenceConstants.DEFAULT_ATTACHMENTS_DIRECTORY);
Index: src/org/eclipse/mylyn/internal/tasks/ui/util/AttachmentUtil.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.mylyn/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/util/AttachmentUtil.java,v
retrieving revision 1.14
diff -u -r1.14 AttachmentUtil.java
--- src/org/eclipse/mylyn/internal/tasks/ui/util/AttachmentUtil.java	27 Aug 2009 00:32:33 -0000	1.14
+++ src/org/eclipse/mylyn/internal/tasks/ui/util/AttachmentUtil.java	5 Sep 2009 19:56:02 -0000
@@ -70,6 +70,16 @@
 
 	private static final String CONTEXT_CONTENT_TYPE = "application/octet-stream"; //$NON-NLS-1$
 
+	private static final String ATTACHMENT_DEFAULT_NAME = "attachment"; //$NON-NLS-1$
+
+	private static final String CTYPE_ZIP = "zip"; //$NON-NLS-1$
+
+	private static final String CTYPE_OCTET_STREAM = "octet-stream"; //$NON-NLS-1$
+
+	private static final String CTYPE_TEXT = "text"; //$NON-NLS-1$
+
+	private static final String CTYPE_HTML = "html"; //$NON-NLS-1$
+
 	public static boolean postContext(AbstractRepositoryConnector connector, TaskRepository repository, ITask task,
 			String comment, TaskAttribute attribute, IProgressMonitor monitor) throws CoreException {
 		AbstractTaskAttachmentHandler attachmentHandler = connector.getTaskAttachmentHandler();
@@ -307,4 +317,26 @@
 		}
 		return Collections.emptyList();
 	}
+
+	public static String getAttachmentFilename(ITaskAttachment attachment) {
+		String name = attachment.getFileName();
+		// if no filename is set, make one up with the proper extension so
+		// we can support opening in that filetype's default editor
+		if (name == null || "".equals(name)) { //$NON-NLS-1$
+			String ctype = attachment.getContentType();
+			if (ctype.endsWith(CTYPE_HTML)) {
+				name = ATTACHMENT_DEFAULT_NAME + ".html"; //$NON-NLS-1$
+			} else if (ctype.startsWith(CTYPE_TEXT)) {
+				name = ATTACHMENT_DEFAULT_NAME + ".txt"; //$NON-NLS-1$
+			} else if (ctype.endsWith(CTYPE_OCTET_STREAM)) {
+				name = ATTACHMENT_DEFAULT_NAME;
+			} else if (ctype.endsWith(CTYPE_ZIP)) {
+				name = ATTACHMENT_DEFAULT_NAME + "." + CTYPE_ZIP; //$NON-NLS-1$
+			} else {
+				name = ATTACHMENT_DEFAULT_NAME + "." + ctype.substring(ctype.indexOf("/") + 1); //$NON-NLS-1$ //$NON-NLS-2$
+			}
+		}
+
+		return name;
+	}
 }
Index: src/org/eclipse/mylyn/internal/tasks/ui/ITasksUiPreferenceConstants.java
===================================================================
RCS file: /cvsroot/tools/org.eclipse.mylyn/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/ITasksUiPreferenceConstants.java,v
retrieving revision 1.10
diff -u -r1.10 ITasksUiPreferenceConstants.java
--- src/org/eclipse/mylyn/internal/tasks/ui/ITasksUiPreferenceConstants.java	24 Jul 2009 12:05:46 -0000	1.10
+++ src/org/eclipse/mylyn/internal/tasks/ui/ITasksUiPreferenceConstants.java	5 Sep 2009 19:56:02 -0000
@@ -83,4 +83,6 @@
 	public static final String PREF_DATA_DIR = "org.eclipse.mylyn.data.dir"; //$NON-NLS-1$
 
 	public static final String DEFAULT_ATTACHMENTS_DIRECTORY = "org.eclipse.mylyn.tasks.ui.attachments.defaultDirectory"; //$NON-NLS-1$
+
+	public static final String PREFERRED_TASK_ATTACHMENT_VIEWER_ID = "org.eclipse.mylyn.tasks.ui.attachments.preferredViewerID"; //$NON-NLS-1$
 }
Index: plugin.xml
===================================================================
RCS file: /cvsroot/tools/org.eclipse.mylyn/org.eclipse.mylyn.tasks.ui/plugin.xml,v
retrieving revision 1.365
diff -u -r1.365 plugin.xml
--- plugin.xml	27 Aug 2009 00:32:33 -0000	1.365
+++ plugin.xml	5 Sep 2009 19:56:02 -0000
@@ -1286,6 +1286,11 @@
       </command>
       <command
             categoryId="org.eclipse.mylyn.tasks.ui.category.editor"
+            id="org.eclipse.mylyn.tasks.ui.command.attachment.open"
+            name="%command.attachment.open.name">
+      </command>
+      <command
+            categoryId="org.eclipse.mylyn.tasks.ui.category.editor"
             id="org.eclipse.mylyn.tasks.ui.command.attachment.openInBrowser"
             name="%command.attachment.openInBrowser.name">
       </command>
@@ -1539,6 +1544,10 @@
             commandId="org.eclipse.mylyn.tasks.ui.command.attachment.openInBrowser">
       </handler>
       <handler
+            class="org.eclipse.mylyn.internal.tasks.ui.commands.OpenTaskAttachmentHandler"
+            commandId="org.eclipse.mylyn.tasks.ui.command.attachment.open">
+      </handler>
+      <handler
             class="org.eclipse.mylyn.internal.tasks.ui.commands.OpenTaskAttachmentInDefaultEditorHandler"
             commandId="org.eclipse.mylyn.tasks.ui.command.attachment.openInDefaultEditor">
       </handler>
@@ -1643,20 +1652,27 @@
       <menuContribution
             locationURI="popup:org.eclipse.mylyn.tasks.ui.editor.menu.attachments?after=group.open">
          <command
-               commandId="org.eclipse.mylyn.tasks.ui.command.attachment.openInBrowser"
-               label="%command.attachment.openInBrowser.label"
+               commandId="org.eclipse.mylyn.tasks.ui.command.attachment.open"
+               label="%command.attachment.open.label"
                mnemonic="O"
                style="push">
          </command>
          <menu
                label="%command.attachment.openInDefaultEditor.menu.label"
                mnemonic="H">
-            <command
-                  commandId="org.eclipse.mylyn.tasks.ui.command.attachment.openInDefaultEditor"
-                  label="%command.attachment.openInDefaultEditor.label"
-                  mnemonic="D"
-                  style="push">
-            </command>
+            <dynamic
+                  class="org.eclipse.mylyn.internal.tasks.ui.commands.OpenTaskAttachmentWithMenu"
+                  id="org.eclipse.mylyn.tasks.ui.command.attachment.openTaskAttachmentWithMenu">
+                  <visibleWhen
+                        checkEnabled="false">
+                     <with
+                           variable="selection">
+                        <count
+                              value="1">
+                        </count>
+                     </with>
+                  </visibleWhen>
+            </dynamic>
          </menu>
       </menuContribution>
       <menuContribution
Index: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerBrowser.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerBrowser.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerBrowser.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerBrowser.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,23 @@
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.mylyn.tasks.ui.TasksUiUtil;
+import org.eclipse.ui.IWorkbenchPage;
+
+public class TaskAttachmentViewerBrowser implements ITaskAttachmentViewer {
+	public String getID() {
+		return "inBrowser";
+	}
+
+	public String getLabel() {
+		return "Browser";
+	}
+
+	public boolean isAvailable(ITaskAttachment attachment) {
+		return attachment.getUrl() != null;
+	}
+
+	public void openAttachment(IWorkbenchPage page, ITaskAttachment attachment) {
+		TasksUiUtil.openUrl(attachment.getUrl());
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentWithMenu.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentWithMenu.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentWithMenu.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentWithMenu.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,118 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui.commands;
+
+import java.util.List;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.jface.action.ContributionItem;
+import org.eclipse.mylyn.internal.tasks.ui.ITaskAttachmentViewer;
+import org.eclipse.mylyn.internal.tasks.ui.TaskAttachmentViewersManager;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
+import org.eclipse.mylyn.internal.tasks.ui.util.TasksUiInternal;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.SelectionAdapter;
+import org.eclipse.swt.events.SelectionEvent;
+import org.eclipse.swt.widgets.Menu;
+import org.eclipse.swt.widgets.MenuItem;
+import org.eclipse.ui.IWorkbench;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.IWorkbenchWindow;
+import org.eclipse.ui.PlatformUI;
+
+public class OpenTaskAttachmentWithMenu extends ContributionItem {
+	private final TaskAttachmentViewersManager manager = TaskAttachmentViewersManager.getInstance();
+
+	public OpenTaskAttachmentWithMenu() {
+	}
+
+	public OpenTaskAttachmentWithMenu(String id) {
+		super(id);
+	}
+
+	@Override
+	public void fill(Menu menu, int index) {
+		List<ITaskAttachment> attachments = AttachmentUtil.getSelectedAttachments();
+		if (attachments.isEmpty() || attachments.size() > 1) {
+			return;
+		}
+
+		// find all interesting editors, and add them into menu
+		ITaskAttachment at = attachments.get(0);
+
+		String prefViewerID = manager.getPreferredViewerID(at);
+
+		int i = 0;
+
+		List<ITaskAttachmentViewer> viewers = manager.getTaskAttachmentViewers(at);
+		for (ITaskAttachmentViewer v : viewers) {
+			MenuItem it = new MenuItem(menu, SWT.RADIO, index + i);
+
+			it.setText(v.getLabel());
+			it.addSelectionListener(new RunAssociatedViewer(it, v));
+			if (prefViewerID != null && prefViewerID.equals(v.getID())) {
+				it.setSelection(true);
+			}
+
+			i++;
+		}
+	}
+
+	private class RunAssociatedViewer extends SelectionAdapter {
+		private final MenuItem menuItem;
+
+		private final ITaskAttachmentViewer viewer;
+
+		RunAssociatedViewer(MenuItem item, ITaskAttachmentViewer handler) {
+			this.menuItem = item;
+			this.viewer = handler;
+		}
+
+		@Override
+		public void widgetSelected(SelectionEvent e) {
+			// this event is fired also for item which gets unselected (i.e. previous 'preferred' viewer)
+			if (!menuItem.getSelection()) {
+				return;
+			}
+
+			IWorkbench wb = PlatformUI.getWorkbench();
+
+			IWorkbenchWindow win = wb.getActiveWorkbenchWindow();
+			if (win == null) {
+				return;
+			}
+
+			IWorkbenchPage page = win.getActivePage();
+			if (page == null) {
+				return;
+			}
+
+			List<ITaskAttachment> attachments = AttachmentUtil.getSelectedAttachments();
+			for (ITaskAttachment ta : attachments) {
+				manager.savePreferredViewerID(ta, viewer.getID());
+
+				try {
+					viewer.openAttachment(page, ta);
+				} catch (CoreException ex) {
+					TasksUiInternal.logAndDisplayStatus("Failed to open viewer", ex.getStatus());
+				}
+			}
+		}
+	}
+
+	@Override
+	public boolean isDynamic() {
+		// depends on selected attachments
+		return true;
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/DownloadAndOpenTaskAttachmentJob.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/DownloadAndOpenTaskAttachmentJob.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/DownloadAndOpenTaskAttachmentJob.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/DownloadAndOpenTaskAttachmentJob.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,133 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.PartInitException;
+
+class DownloadAndOpenTaskAttachmentJob extends Job {
+	private final ITaskAttachment attachment;
+
+	private final IWorkbenchPage page;
+
+	private final String editorID;
+
+	DownloadAndOpenTaskAttachmentJob(String jobName, ITaskAttachment attachment, IWorkbenchPage page, String editorID) {
+		super(jobName);
+
+		this.attachment = attachment;
+		this.page = page;
+		this.editorID = editorID;
+	}
+
+	@Override
+	protected IStatus run(IProgressMonitor monitor) {
+		final String attachmentFilename = AttachmentUtil.getAttachmentFilename(attachment);
+
+		File file = null;
+		try {
+			file = File.createTempFile("attach-", "-" + attachmentFilename);
+		} catch (IOException e) {
+			return new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Failed to download attachment", e);
+		}
+		file.deleteOnExit();
+
+		FileOutputStream fos = null;
+		try {
+			fos = new FileOutputStream(file);
+			AttachmentUtil.downloadAttachment(attachment, fos, monitor);
+			fos.close();
+			fos = null;
+		} catch (IOException e) {
+			closeAndDelete(fos, file);
+			fos = null;
+			return new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Failed to download attachment", e);
+		} catch (CoreException e) {
+			closeAndDelete(fos, file);
+			fos = null;
+			return new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Failed to download attachment", e);
+		} finally {
+			if (fos != null) {
+				try {
+					fos.close();
+				} catch (IOException e) {
+					// ignore ... something bad is happening here
+				}
+			}
+		}
+
+		Display disp = page.getWorkbenchWindow().getWorkbench().getDisplay();
+		if (disp.isDisposed()) {
+			return new Status(IStatus.WARNING, TasksUiPlugin.ID_PLUGIN, "Display is disposed");
+		}
+
+		if (disp.getThread() == Thread.currentThread()) {
+			try {
+				page.openEditor(new FileEditorInput(file, attachmentFilename, attachment.getUrl()), editorID);
+			} catch (PartInitException e) {
+				return new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Cannot open editor", e);
+			}
+
+			return new Status(IStatus.OK, TasksUiPlugin.ID_PLUGIN, "OK");
+		} else {
+			final AtomicReference<IStatus> status = new AtomicReference<IStatus>();
+			final File tmpFile = file;
+
+			disp.syncExec(new Runnable() {
+				public void run() {
+					try {
+						page.openEditor(new FileEditorInput(tmpFile, attachmentFilename, attachment.getUrl()), editorID);
+						status.set(new Status(IStatus.OK, TasksUiPlugin.ID_PLUGIN, "OK"));
+					} catch (PartInitException e) {
+						status.set(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Cannot open editor", e));
+					}
+				};
+			});
+
+			if (status.get() == null) {
+				return new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Cannot open editor");
+			}
+
+			return status.get();
+		}
+	}
+
+	void closeAndDelete(OutputStream os, File file) {
+		if (os != null) {
+			try {
+				os.close();
+			} catch (IOException ex) {
+				// ignore ... we are going to delete the file anyway
+			}
+		}
+
+		if (file == null) {
+			return;
+		}
+
+		file.delete();
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/FileEditorInput.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/FileEditorInput.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/FileEditorInput.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/FileEditorInput.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,68 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import java.io.File;
+
+import org.eclipse.core.resources.IStorage;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.Path;
+import org.eclipse.core.runtime.PlatformObject;
+import org.eclipse.jface.resource.ImageDescriptor;
+import org.eclipse.ui.IPathEditorInput;
+import org.eclipse.ui.IPersistableElement;
+import org.eclipse.ui.IStorageEditorInput;
+
+public class FileEditorInput extends PlatformObject implements IPathEditorInput, IStorageEditorInput {
+	private final File file;
+
+	private final String name;
+
+	private final String tooltipText;
+
+	FileEditorInput(File file, String name, String tooltipText) {
+		this.file = file;
+		this.name = name;
+		this.tooltipText = tooltipText;
+	}
+
+	public IPath getPath() {
+		return Path.fromOSString(file.getAbsolutePath());
+	}
+
+	public boolean exists() {
+		return file.exists();
+	}
+
+	public ImageDescriptor getImageDescriptor() {
+		return null;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public IPersistableElement getPersistable() {
+		// ignore
+		return null;
+	}
+
+	public String getToolTipText() {
+		return tooltipText;
+	}
+
+	public IStorage getStorage() throws CoreException {
+		return new FileStorage(file, name);
+	}
+
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerDefaultEditor.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerDefaultEditor.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerDefaultEditor.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerDefaultEditor.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,41 @@
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.ui.IEditorDescriptor;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.PlatformUI;
+
+public class TaskAttachmentViewerDefaultEditor implements ITaskAttachmentViewer {
+	public String getID() {
+		return "defaultEditor";
+	}
+
+	public String getLabel() {
+		return "Default Editor";
+	}
+
+	public boolean isAvailable(ITaskAttachment attachment) {
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+		IEditorDescriptor d = PlatformUI.getWorkbench().getEditorRegistry().getDefaultEditor(name);
+
+		return d != null;
+	}
+
+	public void openAttachment(IWorkbenchPage page, ITaskAttachment attachment) throws CoreException {
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+		IEditorDescriptor description = PlatformUI.getWorkbench().getEditorRegistry().getDefaultEditor(name);
+
+		if (description == null) {
+			throw new CoreException(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN,
+					"Cannot find default editor for attachment"));
+		}
+
+		DownloadAndOpenTaskAttachmentJob job = new DownloadAndOpenTaskAttachmentJob(
+				"Downloading and opening attachment in default editor", attachment, page, description.getId());
+		job.schedule();
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemExternalEditor.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemExternalEditor.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemExternalEditor.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemExternalEditor.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,52 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.ui.IEditorRegistry;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.PlatformUI;
+
+public class TaskAttachmentViewerSystemExternalEditor implements ITaskAttachmentViewer {
+	public String getID() {
+		return "systemExternalEditor";
+	}
+
+	public String getLabel() {
+		// ignore
+		return "System Editor";
+	}
+
+	public boolean isAvailable(ITaskAttachment attachment) {
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+		return PlatformUI.getWorkbench().getEditorRegistry().isSystemExternalEditorAvailable(name);
+	}
+
+	public void openAttachment(IWorkbenchPage page, ITaskAttachment attachment) throws CoreException {
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+		boolean avail = PlatformUI.getWorkbench().getEditorRegistry().isSystemExternalEditorAvailable(name);
+
+		if (!avail) {
+			throw new CoreException(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN,
+					"Cannot find default editor for attachment"));
+		}
+
+		DownloadAndOpenTaskAttachmentJob job = new DownloadAndOpenTaskAttachmentJob(
+				"Downloading and opening attachment in external editor", attachment, page,
+				IEditorRegistry.SYSTEM_EXTERNAL_EDITOR_ID);
+		job.schedule();
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewersManager.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewersManager.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewersManager.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewersManager.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,90 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+
+public class TaskAttachmentViewersManager {
+	private static final TaskAttachmentViewersManager instance = new TaskAttachmentViewersManager();
+
+	public static TaskAttachmentViewersManager getInstance() {
+		return instance;
+	}
+
+	private final List<ITaskAttachmentViewer> viewers;
+
+	private TaskAttachmentViewersManager() {
+		List<ITaskAttachmentViewer> vl = new ArrayList<ITaskAttachmentViewer>();
+
+		vl.add(new TaskAttachmentViewerBrowser());
+		vl.add(new TaskAttachmentViewerDefaultEditor());
+		vl.add(new TaskAttachmentViewerSystemInplaceEditor());
+		vl.add(new TaskAttachmentViewerSystemExternalEditor());
+
+		viewers = Collections.unmodifiableList(vl);
+	}
+
+	public List<ITaskAttachmentViewer> getTaskAttachmentViewers(ITaskAttachment attachment) {
+		List<ITaskAttachmentViewer> result = new ArrayList<ITaskAttachmentViewer>();
+
+		for (ITaskAttachmentViewer v : viewers) {
+			if (v.isAvailable(attachment)) {
+				result.add(v);
+			}
+		}
+
+		return result;
+	}
+
+	/**
+	 * @param attachment
+	 * @return list of attachment viewers, with preferred viewers in front
+	 */
+	public List<ITaskAttachmentViewer> getSortedTaskAttachmentViewers(ITaskAttachment attachment) {
+		List<ITaskAttachmentViewer> viewers = getTaskAttachmentViewers(attachment);
+
+		String preferred = getPreferredViewerID(attachment);
+		if (preferred == null) {
+			return viewers;
+		}
+
+		// put preferred handler to the beginning
+		int prefIndex = -1;
+		for (int i = 0; i < viewers.size(); i++) {
+			if (preferred.equals(viewers.get(i).getID())) {
+				prefIndex = i;
+				break;
+			}
+		}
+
+		if (prefIndex >= 0) {
+			ITaskAttachmentViewer h = viewers.remove(prefIndex);
+			viewers.add(0, h);
+		}
+
+		return viewers;
+	}
+
+	public String getPreferredViewerID(ITaskAttachment attachment) {
+		return TasksUiPlugin.getDefault().getPreferenceStore().getString(
+				ITasksUiPreferenceConstants.PREFERRED_TASK_ATTACHMENT_VIEWER_ID);
+	}
+
+	public void savePreferredViewerID(ITaskAttachment attachment, String handlerID) {
+		TasksUiPlugin.getDefault().getPreferenceStore().putValue(
+				ITasksUiPreferenceConstants.PREFERRED_TASK_ATTACHMENT_VIEWER_ID, handlerID);
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemInplaceEditor.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemInplaceEditor.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemInplaceEditor.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/TaskAttachmentViewerSystemInplaceEditor.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,52 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.ui.IEditorRegistry;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.PlatformUI;
+
+public class TaskAttachmentViewerSystemInplaceEditor implements ITaskAttachmentViewer {
+	public String getID() {
+		return "systemInplaceEditor";
+	}
+
+	public String getLabel() {
+		// ignore
+		return "In-Place Editor";
+	}
+
+	public boolean isAvailable(ITaskAttachment attachment) {
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+		return PlatformUI.getWorkbench().getEditorRegistry().isSystemExternalEditorAvailable(name);
+	}
+
+	public void openAttachment(IWorkbenchPage page, ITaskAttachment attachment) throws CoreException {
+		String name = AttachmentUtil.getAttachmentFilename(attachment);
+		boolean avail = PlatformUI.getWorkbench().getEditorRegistry().isSystemExternalEditorAvailable(name);
+
+		if (!avail) {
+			throw new CoreException(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN,
+					"Cannot find default in-place editor for attachment"));
+		}
+
+		DownloadAndOpenTaskAttachmentJob job = new DownloadAndOpenTaskAttachmentJob(
+				"Downloading and opening attachment in in-place editor", attachment, page,
+				IEditorRegistry.SYSTEM_INPLACE_EDITOR_ID);
+		job.schedule();
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/ITaskAttachmentViewer.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/ITaskAttachmentViewer.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/ITaskAttachmentViewer.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/ITaskAttachmentViewer.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,39 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.ui.IWorkbenchPage;
+
+/**
+ * Simple interface for attachment 'viewers'. Most viewers are based on existing eclipse editors.
+ */
+public interface ITaskAttachmentViewer {
+	/**
+	 * @return arbitrary string, used to remember preferred viewer
+	 */
+	public String getID();
+
+	/**
+	 * @return name of the editor, displayed to user
+	 */
+	public String getLabel();
+
+	/**
+	 * @param attachment
+	 * @return whether viewer is available for this attachment
+	 */
+	public boolean isAvailable(ITaskAttachment attachment);
+
+	public void openAttachment(IWorkbenchPage page, ITaskAttachment attachment) throws CoreException;
+}
\ No newline at end of file
Index: src/org/eclipse/mylyn/internal/tasks/ui/FileStorage.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/FileStorage.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/FileStorage.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/FileStorage.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,56 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+
+import org.eclipse.core.resources.IStorage;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.PlatformObject;
+import org.eclipse.core.runtime.Status;
+
+class FileStorage extends PlatformObject implements IStorage {
+	private final File file;
+
+	private final String name;
+
+	FileStorage(File file, String name) {
+		this.file = file;
+		this.name = name;
+	}
+
+	public InputStream getContents() throws CoreException {
+		try {
+			return new FileInputStream(file);
+		} catch (FileNotFoundException e) {
+			throw new CoreException(new Status(IStatus.ERROR, TasksUiPlugin.ID_PLUGIN, "Unable to read file", e));
+		}
+	}
+
+	public IPath getFullPath() {
+		// ignore
+		return null;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public boolean isReadOnly() {
+		return true;
+	}
+}
Index: src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentHandler.java
===================================================================
RCS file: src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentHandler.java
diff -N src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentHandler.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ src/org/eclipse/mylyn/internal/tasks/ui/commands/OpenTaskAttachmentHandler.java	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.ui.commands;
+
+import java.util.List;
+
+import org.eclipse.core.commands.AbstractHandler;
+import org.eclipse.core.commands.ExecutionEvent;
+import org.eclipse.core.commands.ExecutionException;
+import org.eclipse.core.commands.IHandler;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.mylyn.internal.tasks.ui.ITaskAttachmentViewer;
+import org.eclipse.mylyn.internal.tasks.ui.TaskAttachmentViewersManager;
+import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
+import org.eclipse.mylyn.internal.tasks.ui.util.AttachmentUtil;
+import org.eclipse.mylyn.internal.tasks.ui.util.TasksUiInternal;
+import org.eclipse.mylyn.tasks.core.ITaskAttachment;
+import org.eclipse.ui.IWorkbench;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.IWorkbenchWindow;
+import org.eclipse.ui.PlatformUI;
+
+public class OpenTaskAttachmentHandler extends AbstractHandler implements IHandler {
+
+	public Object execute(ExecutionEvent event) throws ExecutionException {
+		IWorkbench wb = PlatformUI.getWorkbench();
+
+		IWorkbenchWindow win = wb.getActiveWorkbenchWindow();
+		if (win == null) {
+			return null;
+		}
+
+		IWorkbenchPage page = win.getActivePage();
+		if (page == null) {
+			return null;
+		}
+
+		List<ITaskAttachment> attachments = AttachmentUtil.getSelectedAttachments();
+
+		openAttachments(page, attachments);
+
+		return null;
+	}
+
+	public static void openAttachments(IWorkbenchPage page, List<ITaskAttachment> attachments) {
+		TaskAttachmentViewersManager manager = TaskAttachmentViewersManager.getInstance();
+
+		for (ITaskAttachment a : attachments) {
+			List<ITaskAttachmentViewer> h = manager.getSortedTaskAttachmentViewers(a);
+
+			if (h.isEmpty()) {
+				TasksUiInternal.logAndDisplayStatus("Failed to open editor", new Status(IStatus.WARNING,
+						TasksUiPlugin.ID_PLUGIN, "No suitable attachment viewer found"));
+				continue;
+			}
+
+			ITaskAttachmentViewer dflt = h.get(0);
+			try {
+				dflt.openAttachment(page, a);
+			} catch (CoreException e) {
+				TasksUiInternal.logAndDisplayStatus("Failed to open editor", e.getStatus());
+			}
+		}
+	}
+}